Special Issue of Quaternary International published!

Title: The "Bridging Eurasia" research initiative: Modes of mobility and sustainability in the palaeoenvironmental and archaeological archives from Eurasia. Guest Edited by Mayke Wagner, GuiYun Jin and Pavel Tarasov. Quaternary International (2014).

The current volume is the second in a series of thematic volumes of Quaternary International related to the "Bridging Eurasia" research initiative and Baikal-Hokkaido Archaeology Project (BHAP). The idea of this special volume was first announced in the editorial preface to the first volume entitled "The Baikal-Hokkaido Archaeology Project: Environmental archives, proxies and reconstruction approaches" (Quaternary International, 290-291) and jointly guest-edited by P. Tarasov, D. White, and A. Weber.

"Bridging Eurasia" is a research initiative of the Beijing Branch Office of the Eurasia Department, German Archaeological Institute (http://bridging-eurasia.org/en) and the Institute of Geological Sciences of Free University Berlin (http://www.geo.fu-berlin.de/geol/fachrichtungen/pal/news/2014_Bridging-Eurasia.html). It was first announced at the international conference "Bridging Eurasia: Environmental and Human Dynamics in Southern Siberia - Need for a high-resolution archive" organised in Berlin in May 2010. The research initiative informally unites an international and multidisciplinary team of scientists searching for high-resolution environmental and archaeological archives from Central and East Asia and aiming at correlating archaeological and environmental data at local to regional scale for finding the causality of changes. Regular "Bridging Eurasia" workshops also provide a platform for the exchange of ideas and research results and have contributed the majority of papers to this special volume.

The current volume follows the strategic line of the first volume (http://www.sciencedirect.com/science/journal/10406182/290) in addressing four major tasks: (i) to present current palaeoenvironmental research in central and eastern Asia; (ii) to understand better the nature of environmental archives, archaeological records, and human-environment dynamics in central and eastern Asia; (iii) to indicate gaps in the current knowledge; and (iv) to develop new ideas on how these gaps can be filled in the ongoing and/or future research projects.

The 18 research and review articles included in the special volume are arranged in the following order. The first five papers cover different aspects of environmental and archaeological research in the Lake Baikal region and in neighboring northern Mongolia. The opening paper (Kozyrev et al.) provides a short but comprehensive overview of geological and archaeological research at Late Pleistocene sites in the Tunka rift valley (Lake Baikal region, southern Siberia) and presents new radiocarbon dating of the Palaeolithic layers at several recently investigated sites. The sites represent the earliest evidence of human habitation in the area and allow to extend the hunter-gatherer occupation in the Tunka-Pribaikal'e region to ∼26-45 ka 14C BP. The authors also provide important new information about the age and development of an early microlithic industry in the Cis-Baikal region and stress the necessity of further research for reconstructing climate and environments at and around selected archaeological sites during the second half of the last glacial period, including Marine Isotope Stage 3 (MIS 3) interstadial and the Last Glacial Maximum (LGM, MIS 2), in order to better understand the life conditions and subsistence strategies of the Paleolithic hunter-gatherers in southern Siberia.

The second paper (Müller et al.) presents a new decadal-resolution fossil pollen record from Lake Kotokel near Lake Baikal and a pollen-based reconstruction of the LGM vegetation and environments in the study area during this interval of globally harsh climate. Their results suggest colder and drier than present LGM environments but a general stability of the grassland vegetation in the study region between ca. 26.8 and 19.1 cal ka BP, and support the hypothesis that this productive vegetation could stably serve as a perennial food resource for large populations of herbivores, thus providing favourable environments for the local hunter-gatherers. The following paper (Kostrova et al.) continues discussion of the LGM and late glacial environmental and climate dynamics in the Baikal region inferred from an oxygen isotope record of lacustrine diatom silica. It provides further evidence that Lake Kotokel acted as a strongly evaporative system during the LGM and most of the late glacial interval Baikal for the possibility of applying the trimethylsilylation reaction as an alternative technique for extracting and cleaning diatoms for oxygen isotope analysis.

The fourth paper (Scharlotta and Weber) demonstrates the potential of the individual life history approach, strontium ratios, rare earth and trace elements for reconstructing mobility of middle Holocene foragers in the Lake Baikal region. Their research focuses on six small cemeteries representing the Little Sea and Upper Lena micro-regions as well the Early Neolithic (ca. 8-7.2 cal ka BP) and Early Bronze Age (ca. 5.2-3.4 cal ka BP) periods. The level of hunter-gatherer mobility between and within the analyzed micro-regions was found to be significant with individuals recovered from the Upper Lena showing contact with the Little Sea micro-region along the northwest coast of Lake Baikal. The extensive reference collection includes samples of modern plants, animal bones and water from Lake Baikal and surrounding rivers across the region. It allows robust interpretations of the archaeological material and is of great importance for future research.

The authors of the next paper (Fukumoto et al.) reconstruct the Holocene environmental changes in boreal fen peatland of northern Mongolia using fossil diatom assemblages and Sphagnum taxa composition. Their records suggest that the establishment of peatland at 6.8-6.4 cal ka BP was synchronous with the onset of the mid-Holocene dry climate over Mongolia. However, a number of short-term wet and dry intervals have been also reconstructed during the middle and late Holocene intervals.

The following three papers present results of the palynological studies on the Holocene marine (Rudenko et al.) and lacustrine (Leipe et al., a and b) sediments. The latter two studies demonstrate potentials of pollen and non-pollen palynomorph records from the NW Himalayan lake Tso Moriri (India) for reconstructing Holocene climate change, limnology, and human-environmental interactions. The Tso Moriri pollen-based moisture reconstruction helps to deepen our understanding of the Indus Valley Harappan Civilisation (ca. 5.2-3 cal ka BP). In particular, the prolonged Holocene trend towards aridity, punctuated by an interval of increased dryness (between ca. 4.5 and 4.3 cal ka BP), may have pushed the Mature Harappan urban settlements to develop more efficient agricultural practices in order to deal with the increasingly acute water shortages. The amplified aridity associated with North Atlantic cooling between ca. 4 and 3.6 and around 3.2 cal ka BP further hindered local agriculture, possibly causing the deurbanisation that occurred from ca. 3.9 cal ka BP and eventual collapse of the Harappan Civilisation between ca. 3.5 and 3 cal ka BP.

The next two papers present results of palaeopathological and archeobotanical investigations from Kazakhstan. The paper by Ventresca Miller et al. discusses dental health, diet, and social transformations in the Bronze Age pastoral populations of northern Kazakhstan. Their results suggest that while the archaeological record indicates broad shifts in settlement patterns, demography, and mortuary rituals from the Middle Bronze Age to the Late Bronze Age, there was only a slight shift in dental health observed at the investigated sites of Bestamak (2032-1639 cal BC) and Lisakovsk (1860-1680 cal BC). Comparatively more pronounced frequencies of pathological conditions during the earlier period are attributed by the authors to different patterns of consumption, dental cleaning behaviors, and/or stress. The paper by Spengler et al. provides a comprehensive discussion of the Late Bronze Age agriculture at the archaeological site of Tasbas in the Dzhungar Mountains of eastern Kazakhstan. This article illustrates a multi-resource agropastoral economy at the site during 1490-1260 cal BC and confirms the presence of Bronze Age agriculture in northern central Asia, an area where the nature of early pastoralism and agriculture has been debated for decades. The Late Bronze Age carpological assemblage from Tasbas reveals barley, wheat, green peas, and broomcorn millet (likely produced locally), thus opening new discussions concerning the integration of agriculture into Bronze Age pastoralist economies across central Asia during the second millennium BC. The following paper (Betts et al.) contributes to these discussions by reviewing the origins of wheat and potential pathways for its introduction to China. The authors argue that wheat (Triticum aestivum) is most likely to have been introduced at some time around the late 6th to early 5th millennium BP, and present the two possible introduction pathways: (i) the western, through northern Xinjiang, from Afghanistan or the central Asian oases, and (ii) the north-western, from Eurasian steppes, through southern Siberia and Mongolia. However, this topic certainly deserves more research in the coming years.

The following five papers deal with archaeobotanical and archaeological material from archaeological sites in China. The paper by Sun et al. presents the first results from the early Neolithic Bianbiandong cave site located in Shandong Province. Although not all analyses have been accomplished to date, the Bianbiandong research bridges the gap between late Palaeolithic and Houli culture, which in the Shandong area has been regarded as the earliest Neolithic material. Layer 2 was dated to ca. 5400-4900 cal BC which corresponds to the gap between the Houli and Beixin cultures, or to the very onset of Beixin culture. This indicates that the Houli-Beixin chronological gap is an artifact and might soon be overcome when more finds are systematically radiocarbon dated. The paper by Wu et al. also discusses the earlier than conventionally believed onset of the Neolithic in Shandong Province. This study further contributes to the ongoing discussion on the transition from hunting and gathering to farming in the early Holocene China and demonstrates the presence of diverse wild plants together with a small amount of foxtail and broomcorn millet grains. The study results indicate the exploitation of millet in this part of China as early as 9000-8500 years ago, although foraging remained the common subsistence strategy adopted by contemporary residents of the Shandong Highlands.

The paper by Hein analyses interregional contacts in the prehistoric Liangshan region in south-western China. Using abundant archaeological material, dated from ca. 2500 cal BC to 100 cal AD, from this region, that occupies parts of the modern provinces Sichuan, Yunnan and Guizhou, the author argues that in the emergence of contact networks and acceptance of foreign traits, cultural decisions are just as important as and sometimes even more important than environmental factors.

The next two papers (Kramel et al.; Beck et al.) deal with Bronze Age textile clothes from the Yanghai archaeological site located in the Turfan oasis in western China. Kramel et al. present results of fiber identification, dye analysis, and numerical age determinations. The oldest textile objects represent two pairs of wool trousers dated to 1261-1041 cal BC and 1074-935 cal BC, respectively and the youngest analyzed textile piece is dated to 398-202 cal BC. Analyses of the fibers revealed the use of the colorants alizarin, purpurin, rubiadin, quinizarin, indigo, and indirubin, suggesting utilization of both locally grown plants (i.e. madder) and long-distance trade (i.e. indigo) in the Late Bronze Age Xinjiang region. Beck et al. present the first report on the design and manufacturing process of trousers excavated at Yanghai. The authors argue that the production age (13-10th century BC) corresponds to the climatically-driven spread of mobile pastoralism in eastern Central Asia and predates the widely known Scythian trouser finds. The design of the Yanghai trousers with straight-fitting legs and a wide crotch-piece seems to be a predecessor of modern riding trousers. Together with horse gear and weapons as grave goods in both tombs, these results support former assumptions that the invention of bifurcated lower body garments is related to the new epoch of horseback riding, mounted warfare, and greater mobility by utilizing the speed of the horse. This case study clearly exemplifies the interconnectivity of climate change and human response in terms of changes in lifestyle and technical innovations.

The last two papers present results of climate and vegetation modeling experiments and data-model comparisons with a main focus on Eurasia. The study of Bergemann and Müller applies the BIOME1 vegetation model and published climate data to simulate vegetation dynamics during the last interglacial period (i.e. between ca. 130 and 115 ka) in northern Asia. In this study, conventional and alternative algorithms to calculate a moisture index have been tested. The data-model comparison shows that the modeling results obtained with the newly implemented moisture index are in slightly better agreement with the pollen-based vegetation and climate reconstructions. The paper by Kleinen et al. investigates climate of Marine Isotope Stage (MIS) 11 for four time slices, 416, 410, 400, and 394 ka. The authors compare results from two climate models, the earth system model of intermediate complexity CLIMBER2-LPJ and the general circulation model CCSM3, to reconstructions of MIS 11 temperature, precipitation, and vegetation, mainly from terrestrial records. With regard to temperature and precipitation changes, there is general agreement between models and reconstructions, but reconstructed precipitation changes are often larger than those simulated by the models. The paper emphasizes that limited number of records of sufficiently high resolution and dating quality hinders detailed comparisons between models and reconstructions.

Acknowledgements: We would like to thank all of the contributors to this special volume and hope that the published papers would stimulate future collaborative research and interregional comparisons focused on the Eurasian interiors and contributing to the ongoing projects. The Baikal-Hokkaido Archaeology Project is primarily financed by the Major Collaborative Research Initiative (MCRI) program of the Social Sciences and Humanities Research Council of Canada. The BHAP-related research is further supported through generous contributions from sponsors and collaborating institutions, including Canada Foundation for Innovation, the Leverhulme Trust, University of Alberta, German Archaeological Institute (DAI), Free University Berlin and German Science Foundation (DFG), Russian Foundation for Basic Research (RFBR) and Institute of Geochemistry Russian Academy of Sciences (Irkutsk), Hokkaido University and Japan Society for the Promotion of Science, and the home institutions of the project participants. The "Bridging Eurasia" research is supported by the Center for International Cooperation (FU Berlin), DAI, and DFG, and individual grants from the RFBR, German Academic Exchange Service (DAAD) and Otto Schmidt Laboratory for Polar and Marine Research. The guest editors are grateful to Jan Evers and Christian Leipe (FU Berlin) for their generous help in improving maps and figures in several articles submitted to the special volume, to Patrick Wertmann, Xiaocheng Chen and Joy Zhou (DAI) for translations, to Dominic Hosner (DAI) for technical support, and to all reviewers who contributed their time and expertise in reading, commenting and improving the manuscripts, and to the Editor-in-Chief Prof. Norm Catto for his friendly support and perfect management.